An air cleaner or purifier can employ a high-voltage electric field generated by a high-voltage source, thereby attracting dust in the air to achieve cleaning. A high-voltage source, shown in FIG. 1, generally includes of two opposing metal components a and b. The two metal components with a gas passage can be assembled together with an insulating frame. When a high voltage is applied on the two metal components, a high-voltage electric field is formed between the two metal components. When the air flow passes through the metal components a and b, the dust in the air can be attracted to the metal component b as a result of the high-voltage electric field.
The air cleaner can have different voltages from a transformer using electromagnetic induction principle. A transformer can include: first winding, second winding, and the core. A high-frequency transformer with an operating frequency of more than 10 kHz, high conversion efficiency, small size and other characteristics can be used in switching power supply systems and high-power, high-voltage-frequency inverter transformer systems.